The experimental scheme for particle sizing by detecting the intensity of scattered light with a linear CCD instead of a concentric ring detector was build. The excitation was a compact all-solid-state green laser instead of the conventional He-Ne laser. A full Mie scattering theory was employed to describe the scattering process,through computer fitting of the measured data of scattered intensity vs scattering angle,diameters of the standard polystyrene spheres of 4.91 μm and 9.88 μm dimensions were successfully retrieved. The present apparatus is proven to be simple and effective for sizing particles of 0.7～44.0 μm in diameter.